Assessing the assimilation of Himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from South Asia to the Tibetan Plateau
Emissions from South Asia (SA) represent a critical source of aerosols on the Tibetan Plateau (TP), and aerosols can significantly reduce the surface solar energy. To enhance the precision of aerosol forecasting and its radiative effects in SA and the TP, we employed a four-dimensional local ensembl...
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ftcopernicus:oai:publications.copernicus.org:acp113168 2024-09-15T17:35:13+00:00 Assessing the assimilation of Himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from South Asia to the Tibetan Plateau Zhao, Min Dai, Tie Goto, Daisuke Wang, Hao Shi, Guangyu 2024-01-10 application/pdf https://doi.org/10.5194/acp-24-235-2024 https://acp.copernicus.org/articles/24/235/2024/ eng eng doi:10.5194/acp-24-235-2024 https://acp.copernicus.org/articles/24/235/2024/ eISSN: 1680-7324 Text 2024 ftcopernicus https://doi.org/10.5194/acp-24-235-2024 2024-08-28T05:24:15Z Emissions from South Asia (SA) represent a critical source of aerosols on the Tibetan Plateau (TP), and aerosols can significantly reduce the surface solar energy. To enhance the precision of aerosol forecasting and its radiative effects in SA and the TP, we employed a four-dimensional local ensemble transform Kalman filter (4D-LETKF) aerosol data assimilation (DA) system. This system was utilized to assimilate Himawari-8 aerosol optical thickness (AOT) into the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to depict one SA air pollution outbreak event in spring 2018. Sensitivity tests for the assimilation system were conducted first to tune temporal localization lengths. Comparisons with independent Moderate Resolution Imaging Spectroradiometer (MODIS) and AErosol RObotic NETwork (AERONET) observations demonstrate that the AOT analysis and forecast fields have more reasonable diurnal variations by assimilating all the observations within a 12 h window, which are both better than assimilating the hourly observations in the current assimilation time slot. Assimilation of the entire window of observations with aerosol radiative effect activation significantly improves the prediction of downward solar radiation compared to the free-run experiment. The AOT assimilation with aerosol radiative effect activation led to a reduction in aerosol concentrations over SA, resulting in increased surface radiation, temperature, boundary layer height, and atmospheric instability. These changes facilitated air uplift, promoting aerosol transport from SA to the southeastern TP and leading to an increase in AOT in this region. Text Aerosol Robotic Network Copernicus Publications: E-Journals Atmospheric Chemistry and Physics 24 1 235 258 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
Emissions from South Asia (SA) represent a critical source of aerosols on the Tibetan Plateau (TP), and aerosols can significantly reduce the surface solar energy. To enhance the precision of aerosol forecasting and its radiative effects in SA and the TP, we employed a four-dimensional local ensemble transform Kalman filter (4D-LETKF) aerosol data assimilation (DA) system. This system was utilized to assimilate Himawari-8 aerosol optical thickness (AOT) into the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to depict one SA air pollution outbreak event in spring 2018. Sensitivity tests for the assimilation system were conducted first to tune temporal localization lengths. Comparisons with independent Moderate Resolution Imaging Spectroradiometer (MODIS) and AErosol RObotic NETwork (AERONET) observations demonstrate that the AOT analysis and forecast fields have more reasonable diurnal variations by assimilating all the observations within a 12 h window, which are both better than assimilating the hourly observations in the current assimilation time slot. Assimilation of the entire window of observations with aerosol radiative effect activation significantly improves the prediction of downward solar radiation compared to the free-run experiment. The AOT assimilation with aerosol radiative effect activation led to a reduction in aerosol concentrations over SA, resulting in increased surface radiation, temperature, boundary layer height, and atmospheric instability. These changes facilitated air uplift, promoting aerosol transport from SA to the southeastern TP and leading to an increase in AOT in this region. |
format |
Text |
author |
Zhao, Min Dai, Tie Goto, Daisuke Wang, Hao Shi, Guangyu |
spellingShingle |
Zhao, Min Dai, Tie Goto, Daisuke Wang, Hao Shi, Guangyu Assessing the assimilation of Himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from South Asia to the Tibetan Plateau |
author_facet |
Zhao, Min Dai, Tie Goto, Daisuke Wang, Hao Shi, Guangyu |
author_sort |
Zhao, Min |
title |
Assessing the assimilation of Himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from South Asia to the Tibetan Plateau |
title_short |
Assessing the assimilation of Himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from South Asia to the Tibetan Plateau |
title_full |
Assessing the assimilation of Himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from South Asia to the Tibetan Plateau |
title_fullStr |
Assessing the assimilation of Himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from South Asia to the Tibetan Plateau |
title_full_unstemmed |
Assessing the assimilation of Himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from South Asia to the Tibetan Plateau |
title_sort |
assessing the assimilation of himawari-8 observations on aerosol forecasts and radiative effects during pollution transport from south asia to the tibetan plateau |
publishDate |
2024 |
url |
https://doi.org/10.5194/acp-24-235-2024 https://acp.copernicus.org/articles/24/235/2024/ |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-24-235-2024 https://acp.copernicus.org/articles/24/235/2024/ |
op_doi |
https://doi.org/10.5194/acp-24-235-2024 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
24 |
container_issue |
1 |
container_start_page |
235 |
op_container_end_page |
258 |
_version_ |
1810445531686633472 |